Yancy Noll murder: Road rage turned deadly, or "thrill kill?"

SEATTLE --In 2014 in Seattle, a young engineer admitted during his first degree murder trial that he shot a man driving in the car next to him four times in the head.

Why would a murder defendant admit that? Because he believed the jury would understand his reasons--the engineer said it was the only way he could defend himself against uncontrollable road rage by the other driver.

Engineer Dinh Bowman, at one time considered a genius and child prodigy, says the incident began when he accidentally cut off a car driven by a man named Yancy Noll as both men were driving home from work in August 2012. Bowman says that Noll followed him off the highway and exploded in rage when the cars came to a stop side-by-side at a red light in a quiet residential neighborhood.

Dinh Bowman

King County Prosecutor's Office

“I felt like it was just this crazy bad dream, and I was runnin’ from a monster,” said Bowman who was driving a BMW convertible sports car. “There was sort of-- a stream of swearin’

After a bottle went flying in his direction, Bowman says he feared for his life. Bowman says he retaliated by pulling out his gun and firing. He asked the jury to understand his desperate measures: “If I didn’t do something right then, I was goin’ to die.”

Prosecutors scoffed at Bowman’s defense and claimed that there was another reason entirely that he killed Yancy Noll--a thirst to commit the perfect murder of a stranger, and that this was not road rage but a thrill kill. That story will be featured this week on “48 Hours.”

Road rage is a well-known phenomenon. A detailed AAA study done in the 1990s found that road rage resulted in 218 murders over a seven-year period. Other published reports claim that as many 1,500 injuries and deaths can be traced to road rage in any one year.

Whatever the number, the parade of murders linked to road rage seems never to fade from the headlines.

But why do people explode in rage when behind the wheel and get so aggravated over a perceived or real slight that they drive recklessly or, in Bowman’s case, pull out a gun and fire? What is it about driving that pushes some people’s buttons?

Psychologists point to something called “deindividuation,” defined as “loss of self- awareness and of individual accountability in a group.”

California psychologist Robert Nemerovski has studied road rage extensively. He says that, although most of us don’t think of driving as social, “it consists of countless subtle interpersonal interactions per mile,” he told the Pacific Sun newspaper in an extensive interview.

The Subaru Yancy Noll was driving when he was fatally shot at a Seattle intersection in 2012

"48 Hours"

At the same time, however, cars make us feel anonymous and foster the idea that no one knows who we are as we drive along alone, sometime with tinted windows. The car is, in essence, our domain.

That combination of factors, Nemerovski says “has been shown in several prominent studies to lead to a psychological state called ‘deindividuation,’ which is believed to reduce our inhibitions to perform antisocial behavior. Essentially, if we believe no one can identify us, we are more likely to engage in antisocial, even hostile behavior.”

It is not an accident that the most serious road rage incidents occur when a person is driving alone. If others are present in the car, drivers are less likely to act out in the most extreme way.

If road rage on some level is something that many of us are familiar with, might Dinh Bowman’s unique defense work with the jury? Prosecutors scoffed at his defense and said Bowman was “a student of murder” who’d been training himself to commit the perfect murder for years.

When he found the “right” victim under the “right” circumstances, they said, he blasted away.

Paul LaRosa is a “48 Hours” producer. Watch the investigation into Yancy Noll’s murder and the case against Dinh Bowman in “Student of Murder,” airing Saturday, Sept. 10 at 10 p.m. ET/PT on CBS.